Thermally controlled bottom hole choke



p 1940- w. J. CRITES THERMALLY CONTROLLED BCTTOM HOLE CHOKE Filed July 11 INVEN TOR.

WILBUR J. CRlTE-S Patented Sept. 10, 1940 PATENT OFFICE THERMALLY CONTROLLED BOTTOM HOLE CHOKE Wilbur J. Crites, Bartlesville, Okla., assignor to Phillips Petroleum Company, a corporation of Delaware Application July 11, 1938, Serial No. 218,659

- 10 Claims. (01.16 4) This invention relates to the use of thermal expansion devices for the purpose of imparting motion. It often happens that the magnitude of the motion required is greater than the ca- 5 pacity of the actuating unit or if the unit is of sufiicient capacity the space required is prohibitive, or the stability of the unit is such that it lacks the strength to directly operate the mechanism to which it is applied. The primary object of this invention is to afford a mechanism that is responsive to temperature changes in the translation motion to a complementary mechanism in which the actuating mechanism occupies a minimum amount of space and imparts maximum motion and force to its complement.

This invention further relates to improvements in devices for automatically adjusting at the bottom of an oil well, or at some point below the ground surface, the flow of oil and gas, so 20 that the well may be produced at a rate and/or in such a manner that the least amount of gas will be produced, or at a rate and/or in a manner that less gas will be produced than would be the case without this device. The device may be used to control the production of oil and/or gas coming from the producing formation, or it may be used to control the oil or the oil and gas coming from the producing formation activated by gas injected extraneously. The apparatus herein disclosed is an improvement over the apparatus shown in Patent 1,961,280 issued June 5, 1934, with the present inventor as a joint inventor thereof for carrying forward the same method disclosed in said patent.

The invention further relates to improvements 'in devices for the recording of bottom hole temextraneous gas, to wells in which the fluid is lifted by mechanical means, or to any combination of such lifting forces.

A still further object is to provide a device for energy, to wells flowed by the introduction of i the above mentioned purposes, the adjustment and operation of which is effected by thermal control means, for example, through the expansion and contraction of confined liquids under changing temperatures.

In the production of anyoil well, as the ratio of gas to oil increases, the temperature decreases; and conversely, as the ratio of gas to oil decreases, the temperature increases. Consequently, a device acting in response to temperature changes, I have discovered, may be used to control the flow so that the flow will be increased under increasing temperatures whereby the oil will be produced with less gas than if allowed to flow unrestricted or by a regulation that is unaffected by a gas-oil ratio influence.

It will therefore be understood thatanother object of my invention is to supply means for producing oil at low gas-oil ratios through the use of thermally operated devices responsive to changing temperatures coincident to changing gas-oil ratios whereby the thermally operated device is contactedby the liquid from the: well in the well,

before the fluid passes through the restricting valve or choke.

A still further object of the device is to'use the same as a temperature recording mechanism to determine the variation of temperature existing in the well.

With the foregoing objects outlined and with other objects in view which will appear as the description proceeds, the invention consists in the novel features hereinafter described in detail, illustrated in the accompanying drawings and more particularly pointed out in the appended claims.

In the drawing:

Figure 1 is a vertical sectional view illustrating the application of the device to be placed in an oil well,

Figure 2 is a side elevational view of the choke valve,

Figure 3 is a plan view showing the top of the choke valve, I

Figure 4 is a side elevational view of one of the expansive members showing the approximate shape as derived from the collapsing. of a sphere,

Figure 5 is a vertical sectional view illustrating the application of the device as a temperature recording mechanism.

Referring first to Figure 1, I indicates a string of tubing to be placed within the casing lining a well bore and having a choke housing or case -2- attached on the end of the tubing. The housing 2 is lowered until it reaches the producing formation where the liquid from the well enters chamber 3 in the housing 2 through the perforations 4. The liquid from the well surrounds the expansion fluid containers 5 which are connected together by the-rods 6 and the lowermost .container is connected to the housing bottom through the rod 1. Rod 8 is connected to the uppermost container which in turn connects to the flow choke 9.

The expansion fluid containers 5 are filled with mercury or any other fluid having a high coefficient of expansion and constructed as shown in Figure 4. The body of the containers are made from a light gauge metal and any metal possessing the requisite strength may be employed. The body is first made in the shape of a sphere as shown in dotted line and then pressed to the'final shape, whereby the design of the thermal unit is arrived at by the collapse of a sphere to the point that the collapsing surfaces come in close contact with each other as indicated in Figure 4. Coupling members l0 and H for the connected rods are placed on top and.

perforations 4. The liquid surrounds the containers 5 and the mercury in the containers assume the same temperature as the liquid and are likewise responsive to any change in temperature. The containers are so constructed that the valley portion 5A thereof is the weakest portion of the container and the mercury in expanding or contracting, will exert its-pressure at this point and cause the wall of the container to move upwardly or downwardly as'the case may be. The container is shown in fully extended position in the solid lines of Figure 1 while the dotted lines show the container fully collapsed. As can be seen, the expansion and contraction of the members 5 may be translated into a vertical up and down movement. The vertical movement is transmitted from container to container 5 through the coupling means 6, rod 8 and finally to the choke member 9 where it acts either to seat or to lift the choke 9 from the seat I2. In this manner the oil from the well flows through the space between the valve seat l2 and choke 9 and the amount of oil flowing will be regulated bythe extent of said opening. It is noted that -in the present invention, the thermally responsive means 5 are contacted by the oil and gas flowing from the well before the oil and gas flow through thechoke member and in this manner the thermally re-- tion before the gas has had a chance to expand after going through the choke and tends for more accurate choking of the flow.

As many containers 5 maybe used as are necessary to get the required vertical movement to open or close the choke 9. The temperature differential will be slight so that small movement of each container can be expected so the movement of a number of them must be added together. In placing the device in a well it is first necessary to know the bottom hole temperature so that the containers 5 may be calibrated and number needed determined from the rate of production at which the well is to be flowed. Once the temperature of the well is known the containers 5 are placed in the choke housing 2 and subjected to the well temperature. It' is then determined if the number of containers or ex* pansible members 5 are sufiicient to give the required space or opening between the valve seat l2 and choke 9 to give the production desired. If not, more containers or expansible members 5 are added. When once calibrated and ready for the well hole, the device is removed from the temperature bath. This will allow the mercury in the containers to contract which in turn will pull the choke 9 tightly onto the seat I2. However, it is contemplated placing the'choke in the well immediately, so that little danger of the choke sticking on the valve seat I2 is present. As previously recited, as more and more gas appears with the oil, the temperature in the chamber 3 will be lowered which will tend to contract the mercury in expansible members 5 and thus close the choke 9. Again the important phase of the present disclosure is that the temperature responsive means is on the down side of the choke and not affected by any changes of temperature due to expansion of gas after it passes through the choke means.

Figure 5 shows the application of the vertical movement of expansion fluid containers to a recording temperature gauge to measure the variations of temperature which may. exist in the bottom of a well. A case or housing 20 is shown which may be lowered into the well on a wire line attached to the eye 2|. The bottom of the housing 20 has openings or slots 2lA which allow the fluid from the well to enter the housing. Mounted in the housing 20 and supported on the bottom thereof by means of rod 22 are the mercury filled expansible containers 23 which are of the same construction as previously described for the flow choke means. The ex pansible members 23 are connected together by means of coupling rods 24 as previously described and the operation and functioning of the expansible means is identical with that previously set forth for the flow choke. The uppermost expansible container 23 has the rod 25 mounted thereon and has the shaft 28 rotatably and longitudinally slidable therein. The rod 25 has mounted on its upper end a stylus-21 backed by a coil spring 28. In the upper end of the housing 20 is a clock mechanism 29 which may be of any known design to rotate the shaft 26. Mounted on the shaft 25 and rotatable therewith is the recording cylinder holder 30 which has a wax or soft metal lining 3! around the interior of the cylinder 30. The stylus 21 contacts the wax or soft metal on-the cylinder and makes a recording thereon of any variation in temperature.

In the operation of the recording temperature gauge, it is first necessary to determine the bottom hole temperature by some known means in order to calibrate the expansible containers 23. Once calibrated the device is lowered into the well with the clock mechanism 29 set in motion and the device allowed to remain in the well a requisite length of time. The clock mechanism will rotate the shaft 26 which in turn will rotate the cylinder 30 ke'yedthereto. The stylus 21 mounted on rod 25 will remain stationary and trace a line on the wax or metal coating St on the cylinder 3|].

the expansible containers which in turn will be transmitted to the rod 25 as a vertical movement. This vertical movement up and down of the rod 25 will carry with it the stylus 2? which in turn will trace and record its movement on the wax or soft metal 3! on the cylinder 30. In this man ner a true picture of the variations-in temperature in the well bottom may be had from a study pf the line traced on the coating 3i. Knowing .the coefficient of expansion of mercury and from previous calibration of the expansible containers,

the degrees of change of temperature can easily be calculated.

From the foregoing it is believed that the construction, operation and advantages of my invention may be readily understood by those skilled in the art, and it is apparent that changes may be made in details disclosed, without departing from the spirit of the invention, as expressed in the claims.

What is claimed and desired to be secured by Letters Patent is:

1. Well flow controlling means comprising a passageway for flowing oil and gas from the well, a choke for controlling the flow of oil through the passageway and thermal expansion-means responsive to temperature conditions below said choke and within the well for closing the choke as the temperature decreases and opening the valve as the temperature increases.

2. In a well having tubing therein, a housing member connected to the end of the tubing and having a valve in the upper end of the housing for controlling the flow of oil and gas up the tubing, thermally affected means in the housing below the valve and means controlled by said thermally afiected means for closing the valve as the temperature decreases, and opening the valve as the temperature increases.

3. Well flow controlling means comprising a passageway for flowing oil and gas from the well, a choke for controlling the flow of oil through the passageway and thermal expansion means comprising an expansion fluid containerresponsive to temperature conditions below said choke and within the well for closing the choke as the temperature decreases and opening the Valve as the temperature increases.

4.'We1l flow controlling means comprising passageway for flowing oil and gas from the well, a choke for controlling the flow of oil through the passageway, thermal expansion means com prising an expansion fluid container responsive to temperature conditions below said choke and within the well for closing the choke asthe temperature decreases and opening-the valve as the temperature increases, said container assuming the shape of a collapsed sphere with the collapsing surfaces coming in close contact with each other and the collapsed surfaces expanding outwardly upon expansion of the fluid medium due to temperature change.

5. Well flow controlling means comprising a passageway for flowing oil and gas from the well, a choke for controlling the ficw of oil through the passageway, thermal, expansion means comprising an expansion fluid container responsive Any change in temperature in the well will cause expansion and contraction in to temperature conditionsbelow said choke and within the well for closing the choke as the temperature decreases and opening the valve as the temperature increases, said container assuming the shape of a collapsed sphere with the collapsing surfaces coming in close contact with each other, the collapsed surfaces expanding upon expansion of the fluid medium due. to temperature change and means mounted on the collapsed surfaces for transmitting the movement to the choke member.

6. Well, flow controlling means comprising a passageway for flowing oil and gas from the well, a choke for controlling the flow of oil through the passageway, thermal expansion means comprising a plurality of expansion fluid containers responsive to temperature conditions below said choke and within the well for closing the choke as the, temperature decreases and opening the valve as the temperature increases, said contain ers assuming the shape of a collapsed sphere with the collapsing surfaces coming in close contact with each other, the collapsed surfaces expanding upon expansion of the fluid medium due to temperature change and coupling means mounted between and on the collapsed surfaces for transmitting the movement to the choke member.

'7. In a well having tubing therein, a housing member-connected to the lower end of the tubing and having a valve in the upper end of the housing for controlling the flow of oil and gas up the tubing, thermally affected means in the housing below the valve comprising an expansion fluid container, said container assuming the shape of a collapsed sphere with the Collapsing.

surfaces coming in close contact with each other, and the collapsed surfaces being responsive to the expansion or contraction of the fluid medium due to temperature change for closing the valve as the temperature decreases and opening the valve" as the temperature increases.

8. In a well having tubing therein, a housing member connected to the lower end of the tubing and having a valve in the upper end of the housing for controlling the flow of oil and gas up the tubing, thermally affected" means in the housing below the valve comprising an expansion fluid container, said container assuming the shape of a collapsed sphere with the collapsing surfaces coming in close contact with each other, the collapsed surfaces being responsive to the expansion or contraction of the fluid medium due to temperature change and means mounted on the 001- lapsed surfaces for transmitting their movement to the valve for closing the same as the temperature decreases and opening the valve as the temperature increases.

9. In a well having tubing therein, a housing member connected to the lower end of the tubing and having a valve in the upper end of the housing for controlling the flow of oil and gas up the tubing, thermally aifected means in the housing below the valve comprising a plurality of expansion fluid containers, said containers assuming the shape of a collapsed sphere with the collapsing surfaces coming in close contact with each other, the collapsed surfaces being responsive to the expansion-or contraction of the fluid medium due to temperature change and coupling means mounted between and on the collapsed surfaces for transmitting the movement to the valve member.

10. In a well having tubing therein, a housing member connected to the lower end of the tubing and having a valve in the upper end of the houing for controlling the flow of oil and gas up the 4 tubing, thermally affected means in the housing below the valve comprising a plurality of expansion fluid containers, the lowermost container being rigidly secured to the bottom of the housing by a coupling member, each container assuming the shape of a collapsed sphere with the collapsing surfaces coming in close contact with each other, the collapsed surfaces being responsive to WILBUR J. CRITES. 

